It might look like a ruthless Dalek from "Doctor Who," but the robot prowling the wards at St. Mary's Hospital in London aims to medicate, rather than exterminate.

The robot--dubbed Sister Mary--is part of a "remote presence" trial being run by the department of biosurgery and surgical technology at Imperial College. The aim? To allow doctors to examine patients remotely, using the robot as their eyes and ears.

The 5-foot-3-inch, 215-pound robot being tested out at St. Mary's boasts a camera and tilting screen, runs Windows XP Professional and operates over a wireless 802.11b network that provides a data stream of 600 kilobits per second each way.

"In the clinical trials that are going on at the moment we are looking at patient perception--what they feel about a robot coming in and talking to them--and remote examinations," said surgical specialist registrar Parv Sains, who is working on the trial.

Credit: Steve Ranger

"Sister Mary" at St. Mary's

The robot is controlled remotely by a doctor, whose face appears on the monitor that acts as the robot's "head."

"This is taking telemedicine a step further because you can make the consultation patient-centric," Sains said.

The doctor's control center has a double screen, Webcam and joystick for controlling the robot. In addition to being used for patient consultations, the device can help with mentoring and training medical staff remotely.

It takes about 15 minutes for doctors to learn to drive the robot--and Sains said the mobility is one key aspect of the machine. "A lot of people ask, 'Why not just have a trolley with a Webcam?' But then you need someone to move it about," he said.

Depending on where in the hospital it is, the robot runs on one of two wireless networks--the Imperial College network and the hospital network implemented by Scalable Networks.

It doesn't take patients long to get used to dealing with the droid, Sains said. "The first reaction is 'wow', but once you get stuck into a conversation you lose the feeling that you are talking to a machine because you have the physician's face on the screen," he said.

For example, an accident and emergency team at a village hospital could call on an expert at a distant hospital who could investigate an injury first-hand. Alternatively a specialist at a big hospital could do his rounds quicker by using the robot so that patients could get discharged faster.